Strict accuracy is simply not very high on the list of essentials in speaking to children. Their level of comprehension, their trust and dependency, the joys of imagination, invention and play, all argue for leaving the conventionally realistic world out of many communications with children. The danger arises whenever those who deal with children fall into the trap of confusing "truth" with "truthfulness". It may lead them to confuse fiction and jokes and all that departs from fact with lying. And so they may lose track of what it means to respect children enough to be honest with them. To lie to children then comes to be much like telling stories to them or lies sharing their leaps between fact and fantasy. Often, it also means that the adult needs to lie more and more in order to keep up the appearance or avoid loss of credibility. In addition, the "translation" of the facts into a language the child can understand may be mixed with deception, to play down, for instance, dangers about which nothing can be done. A child told that dressing her wound will not hurt may be reassured enough to lose her anxiety, an over-casual child may be appropriately "scared" into caution in dangerous situations, but they are also learning that grownups bend the truth when it suits them. All these factors -- the need for shielding and encouragement, the low priority on accuracy, and the desire to get meaningful information across in spite of difficulties of understanding or response -- contribute to the ease with which children are deceived. The very privacy of parent-child communication, make paternal deception no small matter, and an extremely grave matter when there is as a result the risk of mental or physical harm to the child.
Children, more than others, need care, support, protection. Because they are more vulnerable and more impressionable than adults, they cannot always cope with what they hear. Their efforts, however rudimentary, need encouragement and concern, rather than "objective", truthful evaluation. Unvarnished facts, thoughtlessly or maliciously conveyed, can hurt them, even warp them, render them callous in self-defence. To keep up appearances in a family, of love between parents, wellbeing and sufficiency, stability and so on, are not lies but essential for a child's welfare.